Antibodies, Monoclonal, Murine-Derived; Biogenesis; Enzymes; Phosphoprotein Phosphatases; Signal Transduction; Tumor Suppressor Proteins
Most cellular processes involve the reversible phosphorylation of proteins. Consequently, kinases and phosphatases catalyzing the phosphorylation/dephosphorylation reactions are important regulators of all aspects of life. My lab is studying protein phosphatase 2A (PP2A), a highly conserved phosphoserine/-threonine specific multi-subunit enzyme family, with the goal to elucidate the molecular mechanisms of PP2A biogenesis. Dysregulation of PP2A plays a causative role in human diseases such as Alzheimers and cancer. Understanding the complex regulation of this enzyme family is key for the development of novel therapeutic strategies. Our work in yeast has unraveled some of the basic principles of PP2A biogenesis, which laid the foundation to the present biogenesis model. Currently, we analyze PP2A regulation by phosphorylation and its functional consequences on PP2A activity and specificity.
A second focus of the lab is business-orientated and deals with the generation of monoclonal antibodies for research and diagnosis and the development of novel approaches to improve antibody specificity. For example, we generated and licensed the worldwide first monoclonal antibodies against the CRISPR/Cas9 endonuclease and developed the anti-BLUE and anti-RAINBOW antibodies, which allow the simultaneous detection of the protein of interest and the prestained molecular weight markers on Western blot exposures.
Techniques, methods & infrastructure
- Biochemical, cell biological, and molecular biology techniques
- Protein-protein interactions assays (M-Track, biotin ligase, 2-hybrid assay)
- Analysis of enzyme kinetics/activities
- Monoclonal antibody generation, Monoclonal antibody facility
- Expression and purification of recombinant proteins
- Model organisms: yeast, mouse and mammalian cells
- Frohner, I.E. et al., 2020. PP2AC Phospho-Tyr307 Antibodies Are Not Specific for this Modification but Are Sensitive to Other PP2AC Modifications Including Leu309 Methylation. Cell Reports, 30(9), pp.3171–3182.e6. Available at: http://dx.doi.org/10.1016/j.celrep.2020.02.035.
- Schüchner, S. et al., 2020. The Myc tag monoclonal antibody 9E10 displays highly variable epitope recognition dependent on neighboring sequence context. Science Signaling, 13(616), p.eaax9730. Available at: http://dx.doi.org/10.1126/scisignal.aax9730.
- Frohner, I.E. et al., 2020. Antibodies recognizing the C terminus of PP2A catalytic subunit are unsuitable for evaluating PP2A activity and holoenzyme composition. Science Signaling, 13(616), p.eaax6490. Available at: http://dx.doi.org/10.1126/scisignal.aax6490.
- Leonard, D. et al., 2020. Selective PP2A Enhancement through Biased Heterotrimer Stabilization. Cell, 181(3), pp.688–701.e16. Available at: http://dx.doi.org/10.1016/j.cell.2020.03.038.
- Zuzuarregui, A. et al., 2012. M-Track: detecting short-lived protein-protein interactions in vivo. Nature Methods, 9(6), pp.594–596. Available at: http://dx.doi.org/10.1038/nmeth.2017.